This invention broadly relates to clamps. More particularly, this invention relates to a T-slot hold down clamp that is adjustable to various positions in its fully closed or clamped position.
Toggle and hold down clamps have been used and known in the art for many years. The typical hold down or toggle clamp includes a clamping arm which pivots between a released and clamped position. Many of these prior art clamps are used to hold work pieces in place for processing, for clamping two objects to one another, or for clamping an object to a work table or other work surface. Some of these prior art hold down clamps are a variety known as a T-slot clamp, wherein the clamp is arranged within a T-slot arranged on a work surface or work table. The T-slot clamp is held in place within the T-slot via a bolt or other fastener and is capable of sliding along the T-slot within the table to a predetermined position to hold a work piece during operations thereon. These T-slot clamps are capable of being arranged in a variety of positions with relation to the work piece and within the work table having the T-slots arranged therein. The prior art hold down clamps generally are quickly engageable and disengageable to the work piece or object being held. They also provide a considerable holding and clamping force which enables them to hold the work piece or objects securely during operations thereon.
Many of these prior art hold down clamps hold the clamped position through a variety of means, these means include maintaining the force applied to the bar or arm of the clamp. Other prior art clamps use a releasable assembly for a clamp. Further, prior art clamps create a holding force by passing the links of the toggle clamps into an over center position, the over center position subjects the links and the pivot points of the clamp to very high loads resulting in increased wear and potential deformation of the clamp components thereby reducing the life of the clamp. Many of these prior art clamps also are designed to create their toggle or over center force at one predetermined position with relation to the object being held thus precipitating the need for numerous clamps if the objects being held have varying heights and widths onto which the clamp is being engaged. There have been problems with prior art clamps releasing due to vibration and other unforeseen forces during the operations being performed on the work pieces which are held by the clamp. There also have been problems with the prior art clamps in maintaining a predetermined hold down force needed to keep the objects being held at a precise position such that operations can be performed to predetermined specifications.
Therefore, there is a need in the art for an improved T-slot clamp that is more robust, has greater strength and interchangeability than prior art clamps. There also is a need in the art for an improved T-slot clamp that is capable of being adjusted to a variety of heights in its fully clamped or toggled position to allow for one clamp to perform multiple operations on a variety of sized components being held via the T-slot clamp. There also is a need in the art for a T-slot clamp that is capable of one handed operation including one handed adjustment of the bar member. There also is the need in the art for an improved T-slot clamp that is capable of being locked in its fully closed or clamped position.